Both fundamental and clinically related studies were conducted of immune function and cancer. The genetic material determining the structure of kappa light chains and gamma and mu heavy chains of antibody molecules was investigated. The V regions and individual CH domains of heavy chain genes were shown to be separated by noncoding intervening sequences. The cellular devices for deleting the noncoding regions and bringing together the active areas post transcription are under investigation. Membrane changes following antigen recognition demonstrated rapid replacement of receptors and responding cell membranes. Tolerant immune cells were, however, unable to replace surface antigen receptors, indicating a possible mechanism for immune tolerance. Three different categories of B cells were identified in the circulation following booster immunization with tetanus or diphtheria toxoid. Studies of suppressor systems distinguished separate systems for regulating IgE (from IgG and IgM) synthesis, for specific antibody response as well as functionally distinct subpopulations with and without adenosine receptor. New techniques were introduced to allow separate study of binding and cytotoxic steps in T cells, NK and K cell cytotoxicity systems. A pre-NK population was identified and will be characterized. Subpopulations of monocytes (macrophages) were identified, separated and shown to differ in functional properties. Studies of these lymphocyte and monocyte subgroups in disease have been initiated. Preliminary explorations of intralymphatic immunotherapy with irradiated tumor vaccines were conducted in malignant melanoma and several tumors. Evidence of immune response and possible benefits were seen.